The comparison of the CD layer via the M1 with the SACD layer via the Sony's DACs is hardly a way to compare the media. That there was a difference is not surprising but I do not know how one can draw much meaning from it.

From the measurements that John Atkinson reported, it looks like the M1 takes in 24/192 but that the output is limited to more like 24/96. The output for 24/96 input starts to dive after about 40 KHz as expected. Other high end DACs reach out to 60KHz + output for 192 input. But with the M1 is looks like the 192 KHz signals doesn't do that. Seems like they updated in input to 192KHz but not the rest of the chain. Am I reading this right? Do you get any advantage from a 192KHz input with the M1?